1. Field of the Invention
The present invention relates to a quick connector, for example, to be adapted for connection of gasoline fuel piping for a motor vehicle, more specifically, a quick connector having a connection verifying function for verifying that a pipe is correctly fitted in and connected to the quick connector.
2. Description of the Related Art
In a fluid piping such as gasoline fuel piping wherein a connector or a quick connector is used for connecting a pipe and a mating member, for example, the pipe includes an inserting end portion on an inserting end thereof wherein an annular engaging projection is formed on an outer peripheral surface, while the connector is provided with retainer means. The inserting end portion of the pipe is relatively inserted into the connector so that the annular engaging projection snap-engages with the retainer means to provide locking relation between the pipe and the connector, and thereby the connector is connected to the pipe. The connector or the quick connector used in this manner has a tubular connector housing including a tube connecting portion on one axial end and a retainer mounting portion on the other axial end thereof, and a retainer mounted on or in the retainer mounting portion of the connector housing. When the inserting end portion of the pipe is inserted into an opening or aperture of an axial edge of the connector or the connector housing, the annular engaging projection of the pipe advances in the connector while deforming the retainer, and the annular engaging projection, for example, passes through the retainer or reaches an engaging portion such as an engaging slit formed in the retainer, namely, the annular engaging projection reaches a connecting position, the retainer returns, for example, to its original shape before deformed due to its spring-back force, and is brought into snap-engagement (lock engagement) with the annular engaging projection.
Hence, in case of this type of a quick connector, an operator has to connect the pipe and the quick connector with a great deal of attention. Otherwise, there is a possibility that the inserting end portion of the pipe is not fully inserted into the retainer mounting portion of the connector housing, namely, so-called incorrect connection, wherein, for example, the annular engagement projection does not pass through the retainer or does not reach an engaging portion of the retainer, is made between the quick connector and the pipe. However, in case of a piping system subject to operation while the pipe is incorrectly connected to the quick connector, the inserting end portion of the pipe is retracted to a position of sealing member that provides a seal between the connector housing and the pipe, namely is moved to the other axial end during operation, and sealing property by the sealing member between the connector housing and the pipe is insufficient or becomes lowered, and, as a result, an internal fluid might leak out.
Then, connection verifying means for a pipe and a quick connector is demanded in order to verify fit-in relation between the pipe and the quick connector. One of known type of such connection verifying means for a pipe and a connector is a checker that is configured to be fitted to or mounted on or in the connector housing before the pipe is inserted in a connector housing. The checker can be removed from the connector housing only when the pipe is correctly fitted in or connected to the connector housing. However, such connection verifying means allows an operator to verify correct connection between the pipe and the connector only once. So, another connection verifying means of double-lock type is used that allows the operator to verify complete connection each time the pipe is connected to the connector housing, that is, to verify correct connection even when the pipe that is once disconnect from the connector is reinserted in the connector housing (for example, refer to Patent Document 1). Here, a retainer is configured to be fitted or mounted in the connector housing after the pipe is inserted in the connector housing. And, when the pipe is incorrectly fitted in the connector housing, the annular engaging projection becomes an obstacle to mount the retainer on the connector housing.
[Patent Document 1] JP-A 2002-276878
And, in such connection verifying means, the retainer is mounted on the connector housing every time the pipe that is once disconnected from the connector housing is connected to the connector again, and therefore it is always possible to detect incorrect connection between the pipe and the connector. Further, since the retainer itself has connection verifying function, it is advantageous that the connector can be provided at lower cost compared to the case where the connection verifying device is configured separately from the retainer.
However, in this case, the connector is not configured as a quick connector. Namely, for connection of the pipe and the connector housing, an operator is required to perform two annoying operations, i.e., insertion of the pipe into the connector housing and mounting of the retainer on the connector housing. This complicates connecting work for the pipe and the connector. And, there could be a fear that connection of the pipe is finished without performing later subsequent process such as mounting of the retainer. So, it is difficult to achieve high reliability with piping arrangement with the connector as disclosed in the Patent Document 1.
Under the circumstances described above, it is an object of the present invention to provide a quick connector that is inexpensive and allows an operator to easily construct secure piping arrangement.